title: Improved late gadolinium enhancement MR imaging for patients with implanted cardiac devices.
abstract: OBJECTIVE
  To propose and test a modified wideband late gadolinium enhancement (LGE) magnetic resonance (MR) imaging technique to overcome hyperintensity image artifacts caused by implanted cardiac devices.
  
  
  METHODS
  Written informed consent was obtained from all participants, and the HIPAA-compliant study protocol was approved by the institutional review board. Studies in phantoms and in a healthy volunteer were performed to test the hypothesis that the hyperintensity artifacts that are typically observed on LGE images in patients with implanted cardiac devices are caused by insufficient inversion of the affected myocardial signal. The conventional LGE MR imaging pulse sequence was modified by replacing the nonselective inversion pulse with a wideband inversion pulse. The modified LGE sequence, along with the conventional LGE sequence, was evaluated in 12 patients with implantable cardioverter defibrillators (ICDs) who were referred for cardiac MR imaging.
  
  
  RESULTS
  The ICD causes 2-6 kHz in frequency shift at locations 5-10 cm away from the device. This off-resonance falls outside the typical spectral bandwidth of the nonselective inversion pulse used in conventional LGE, which results in the hyperintensity artifact. In 10 of the 12 patients, the conventional LGE technique produced severe, uninterpretable hyperintensity artifacts in the anterior and lateral portions of the left ventricular wall. These artifacts were eliminated with use of the wideband LGE sequence, thereby enabling confident evaluation of myocardial viability.
  
  
  CONCLUSIONS
  The modified wideband LGE MR imaging technique eliminates the hyperintensity artifacts seen in patients with cardiac devices. The technique may enable LGE MR imaging in patients with cardiac devices, in whom LGE MR imaging otherwise could not be used for diagnosis.
authors.affiliation: From the Department of Radiological Sciences, David Geffen School of Medicine, University of California-Los Angeles (S. Rashid, S. Rapacchi, K.S., J.P.F., P.H.); UCLA Cardiac Arrhythmia Center, UCLA Health System, Los Angeles, Calif (M.V., R.T., K.S., P.H.); and Biomedical Physics Inter-Departmental Graduate Program, University of California-Los Angeles, Los Angeles, Calif (J.P.F., P.H.).
authors.forename: Shams
authors.initials: S
authors.lastname: Rashid
authors.forename: Stanislas
authors.initials: S
authors.lastname: Rapacchi
authors.forename: Marmar
authors.initials: M
authors.lastname: Vaseghi
authors.forename: Roderick
authors.initials: R
authors.lastname: Tung
authors.forename: Kalyanam
authors.initials: K
authors.lastname: Shivkumar
authors.forename: J Paul
authors.initials: JP
authors.lastname: Finn
authors.forename: Peng
authors.initials: P
authors.lastname: Hu
mesh_terms: D016477:Artifacts; D003198:Computer Simulation; D003287:Contrast Media; D017147:Defibrillators, Implantable; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D019047:Phantoms, Imaging
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA